(57) The application describes a method for producing a population of cardiac stromal cells from pluripotent stem cells. Specifically, the method relates to (i) inducing epithelial-mesenchymal transition of pluripotent stem cell derived epicardial cells and (ii) amplifying the number of cardiac stromal cells in serum-free conditions. These cardiac stromal cells can be mass produced according to the described method and said cells maintain the expression of CD90, CD73 and CD44 in at least 80% of the cardiac stromal cells. Furthermore, the application relates to a population of cardiac stromal cells, which are pluripotent stem cells derived and wherein at least 80% of the cardiac stromal cells express CD90, CD73 and CD44. Said cardiac stromal form the basis for several in vitro and in vivo applications such as the production of engineered organ tissue and the support of, for example, heart repair. Also, a serum-free culture medium for the amplification of cardiac stromal cells is provided herein.